diff --git a/include/boost/unordered/detail/allocator_helpers.hpp b/include/boost/unordered/detail/allocator_helpers.hpp
index dbba5046..bdc8d8e6 100644
--- a/include/boost/unordered/detail/allocator_helpers.hpp
+++ b/include/boost/unordered/detail/allocator_helpers.hpp
@@ -27,7 +27,14 @@
 #include <boost/utility/addressof.hpp>
 
 #if !defined(BOOST_UNORDERED_USE_ALLOCATOR_TRAITS)
-#define BOOST_UNORDERED_USE_ALLOCATOR_TRAITS 0
+#   if defined(__GXX_EXPERIMENTAL_CXX0X__) && \
+            (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 7))
+#       define BOOST_UNORDERED_USE_ALLOCATOR_TRAITS 1
+#   endif
+#endif
+
+#if !defined(BOOST_UNORDERED_USE_ALLOCATOR_TRAITS)
+#   define BOOST_UNORDERED_USE_ALLOCATOR_TRAITS 0
 #endif
 
 #if BOOST_UNORDERED_USE_ALLOCATOR_TRAITS
diff --git a/test/unordered/allocator_traits.cpp b/test/unordered/allocator_traits.cpp
index ef7f61fe..777ac14e 100644
--- a/test/unordered/allocator_traits.cpp
+++ b/test/unordered/allocator_traits.cpp
@@ -132,7 +132,7 @@ void test_allocator1()
     BOOST_MPL_ASSERT((boost::is_same<typename traits::size_type,
         std::make_unsigned<std::ptrdiff_t>::type>));
 #else
-    BOOST_MPL_ASSERT((boost::is_same<traits::size_type, std::size_t>));
+    BOOST_MPL_ASSERT((boost::is_same<typename traits::size_type, std::size_t>));
 #endif
     BOOST_MPL_ASSERT((boost::is_same<traits::difference_type, std::ptrdiff_t>));
     BOOST_MPL_ASSERT((boost::is_same<traits::pointer, int*>));